1. Field on the Invention
The present invention pertains to flexible foam compositions and in particular to flexible polyurethane flame-resistant foam compositions and methods for the preparation thereof. More particularly, the present invention relates to the preparation of flexible polyurethane flame-resistant foam compositions which contain an effective amount of dicyanodiamide, oxamide and biuret as the sole flame retardant.
2. Description of the Prior Art
The preparation of flexible polyurethane flame-resistant foam compositions are generally well known as evidenced by the following prior art. U.S. Pat. No. 4,022,718 teaches the preparation of high resilience cold-cured polyurethane foams incorporating 2,3-dibromo-1,4-butenediol as a chain extender and flame-retardant component. U.S. Pat. No. 4,147,847 teaches a method of preparing flexible, flame-retardant, polyurethane foams by employing specific foam stabilizers which reduce the required amount of normal flame-retardant additives. U.S. Pat. No. 4,162,353 teaches the preparation of flexible polyurethane foams incorporating therein a halo-substituted alkyl phosphate such as, for example, tris(2-chlorethyl)-phosphate and an unsubstituted trialkylphosphate such as, for example triethylphosphate. U.S. Pat. No. 4,293,657 teaches the use of melamine polyol dispersions wherein the melamine particles are ground in situ with the polyol and wherein specific dispersion stabilizers are employed. U.S. Pat. No. 4,221,875 teaches the use of melamine in rigid polyurethane foam. U.S. Pat. No. 4,258,141 teaches the use of various cyanic acid derivatives in preparing flame resistant flexible foams but teaches away from using toluene diisocyanate as the isocyanate compound.